We are running NAV 2018.
I want to update a large number of customer records - specifically address details and tax code that were omitted first time around.
I am using the configuration package created when we loaded the system. I exported the customer table to Excel, updated the records and want to import the same file back into NAV
When I apply the data I get errors on all records "you may not enter numbers manually". The system auto-assigns a number to NEW customers as CUSTnnnn
As the records all exist I was expecting it to update, not try to add.
Is there some other setting I should be using?